Motor fuel



, lie Brewing.

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i tive agent furmshin Patented Apr. 11, I

uu rso sures TDBK, A CQBZOB ATION OF DELAWARE My present invention relates'to an in proved motor fuel having anti-mock qual ties. Among the various anti-mock ingredlents containing metals which have beeen pro posed, tetracthyl lead has thus far been the most widely adopted. its use, however, is not free from dificulties, chief of which are its poisonous character both before and after combustion and the fact that the use oil the ure substance results in the deposition or eyers of low oxide'of obiiectioneble choreoter which edhere to the cy 'nder walls, valves end sperk plugs, end which necessitete the presence in the cylinder of some substance which by its solvent or other action prevents or removes such lsyers us they ere formed. Such aids to the use of tctreethyl lead, the most successful of which heve been certain halogen compounds, have, however, on appreciable corrosive efiect upon the motel parts of the engine, and their use is therefore limited; I

@ther gasoline oluble, volatile metal compounds, perticularly the carbonyls of iron, nickel, and cobalt, have been found to possess marked anti-knock properties. Of these, iron carbonyl has many advantages, includin its relative non-poisonous cheracter, availability and ease of menuiacture. Its use, however, is attended with the dificulty that it causes the deposition of a layer or coating of iron oxide on the'sperlr lug insulators, the dielectricstren h of w ich coating rapidly decreases as t e temperature in the cylinder increases until after a time the.

cylinder misses fire, because of the more or less complete short circuiting of the spark plug electrode. a

I have now discovered that the conducting action of the deposit formed by iron carbonyl on the park plug mag be rendered inefiective by incorporating in t e fuel mixtur: a correcwhich are likewise eposited on the s ark plugs but which-are themselves non-con ucting and by their presence nullify the conductin efiect of such oxide layers. 7

iurthermore' I have found the use of the corrective agents mentioned effective not only to inhibit its conducting action ofthe oxide stub ity, I

combustion products OI LONG- IQBAHD GREY, NEW

' moron rum. Application filed July 16, 1%8. serial no. $98,816. Y A

layer as it is deposited but its continued use to reduce to a desired degree the conductivity of such layers as are already formed.

In the class of substances mentioned as corrective agents those which if have thus far round most efiective are volatile gasoline soluble compounds of iced end of nickel. @t these, 1 prefer respectively tetreethyl lend and nickel carbonyl. he preferred enemples oi my improved anti-mock incl mixture, ll glve the following:

1. 1 gallon of low compression duel such as ordina gasoline, 7 cc. iron oer nyl, 0.35 cc. tetracthyl lend.

Instead of the pure tetreethyl lend ll may use .an equlvalent amount oi the so-celled ethyl fluid containing in addition to the tetreeth 1 lead, di-methyl bromide end monochlornn thelene although the use of the pure subs'tnnoe is to be preferred.

2. lgallon of low compression fuel such as ordinary gasoline,

7 cc. iron cerbon l, 0.1 cc. nickel carbonyl.

- The foregoing proportions may he vnried considerably and beneficial results obtcined. Thus where the spark plugs have'been' badly coated with a conducting oxide, the amount of the corrective agent may be increesed somewhat, whereas for ordina use the proportion thereof may be consi erably decreased l{rein the values given and satisfactory action However, I may say that the iron carbonyl may be utilized with the gasoline in the proportion of about 5 to 18 cc. of iron carbonyl to each gallon of gasoline, depending upon the compression ratio and other factors offecting detonation; If the compression ratio is high, more iron carbonyl will be used. The tetraethyl may amounts varying from 0.1 cc. to 2 cc. for each gallon of gasoline. In all cases it is desire Is to keep the proportion of tetraethyl lead as low as possible and still do the work. The amount of corrective agent required depends in considerable part upon the design PATENT M e ASSIGNOR, BY ME AESIGNKENTS, TO

be used es a corrective in and operating temperature of the spark plug. The cooler the temperature at which the plug operates. the less corrective agent is necessary. The amount of corrective agent also depends upon the amount or" iron carbonyl used the larger quantity of corrective being used it a larger amount of iron carbonyl is employed. The iron carbonyl tends to foul the spark plug, and the corrective tends to prevent this. i

The ellect of my improved corrective agents is best seen by the following results of tests in which the effective resistance of the spark plug insulator is measured while the engine is being run:

A mixture of gasoline and iron carbonyl in a proportion of one gallon gasoline to 15 cc. I*e(CO) was run in an engine until the effective resistance of the coated spark plug insulator fell to at megohms at which point the engine started to miss. Under conditions of the test one hour and thirty minutes were required tobring about this condition, start ing with a clean plug. Then tetraethyl lead in the proportion of 0.2 cc. Pb(C H }1 to one gallon of the mixture was added and the operation of the engine continued for twenty minutes during which time the effective resistance of the spark plug insulator had risen to 6 megohms, a value above that at which missing took place. The motor was then stopped and operation continued with a fuel mixture consisting of gasoline and iron carbonyl alone, whereupon in ten minutes the resistance had dropped to 3 megohms, or 1 'megohm below the value at which missing was observable. To the same gasoline and iron carbonyl mixture was now added 0.1 cc. nickel carbonyl; after thirty minutes of operation the resistance had attained a value of 6 megohms at which the engine continued to operate satisfactorily.

I am unable at this time to present a theory of action ofmy improved corrective agents which is in every respect satisfactory and is exclusive of other theories. However, I may state that the action of my corrective agents is as if the non-conducting particles deposited on the insulating surface simultaneously with the conducting particles in effect surround such conducting particles so as to render the whole layer substantially non-conducting. When a spark plug having a previously formed conducting layer of iron oxide is submitted to the action of my improved correctives the action is somewhat more diflicult to explain. It is suggested, however, that their action may be due to. either or both of the following causes: (1) The newly formed layer containing the oxide of the corrective metal, which layer is relatively non-conducting, acts to shield the inner conductive layer from'the radiant heat,

and for that reason keeps down its temperature and correspondingly its conductive effeet. 2) The oxide of the corrective metal, being nely divided and very likely of colloidal dimensions, is able to penetrate even the conductive coating so as to render it nonconducting.

In addition to the foregoing it should be kept in mind that the oxides of the corrective metals may also have the property of absorbing heat during the firin of the char e in the cylinder, this heat being given ofi' ater during the expansion stroke of the piston. In this manner the coating of iron oxide is prevented from attaining a sufficiently high temperature during the combustion period to render it conductive to a point where a miss occurs.

The advantages of my invention will be easily apparent. In the first place, even where lead is used as the corrective agent the amount present is reduced very greatly over that obtaining in the usual leaded gasoline, being only about one-tenth or less of such amount, whereby the danger of lead poisoning is minimized. In addition, because of the very small amount of lead present, the use of the halogen compounds mentioned which, as stated, have an appreciable corrosive effect upon the engine parts, may be entirely eliminated. Furthermore, by the use of other metals having the properties specified for such corrective agents as for example nickel, the danger of oisoning, at least so far as products of com ustion are concerned may be entirely eliminated. It will furthermore be noted that following the disclosure herein the corrective agent may have the additional advantage of being a valuable anti-knock ingredient in itself whose roperties in this respect are thus added to t ose of the main ingredient.

My invention then consists broadly in the use with a metallic anti-knock compound which under the conditions obtaining in the engine cylinder will form a conducting deposit on the spark plugs, of a compound which will form a product depositing with the conducting deposit of such a nature that the combination is non-conducting.

I claim:

'1 An improved motor fuel compnsm a low compression fuel, an anti-knock su stance comprising iron carbonyl, and a corrective agent comprising tetraethyl lead, the ratio of anti-knock substance and corrective agent being substantially ten to one.

In testimony whereof I have aflixed my sig nature to this specification.

R. T HURLEY. 

